U.S. patent application number 15/487549 was filed with the patent office on 2017-12-28 for optical device including slot and apparatus employing the optical device.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. The applicant listed for this patent is KOREA UNIVERSITY RESEARCH AND BUSINESS FOUNDATION, SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Jineun KIM, Suyeon LEE, Q Han PARK, Yeonsang PARK, Younggeun ROH.
Application Number | 20170370773 15/487549 |
Document ID | / |
Family ID | 60676807 |
Filed Date | 2017-12-28 |
United States Patent
Application |
20170370773 |
Kind Code |
A1 |
KIM; Jineun ; et
al. |
December 28, 2017 |
OPTICAL DEVICE INCLUDING SLOT AND APPARATUS EMPLOYING THE OPTICAL
DEVICE
Abstract
An optical device including slots and an apparatus employing the
optical device are provided. An optical unit device for selectively
transmitting electromagnetic waves of a wavelength range, includes
a material layer including slots. A gap between the slots has a
distance such that the optical unit device has a Q-factor of about
5 or more.
Inventors: |
KIM; Jineun; (Suwon-si,
KR) ; ROH; Younggeun; (Seoul, KR) ; PARK; Q
Han; (Seoul, KR) ; PARK; Yeonsang; (Seoul,
KR) ; LEE; Suyeon; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO., LTD.
KOREA UNIVERSITY RESEARCH AND BUSINESS FOUNDATION |
Suwon-si
Seoul |
|
KR
KR |
|
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
KOREA UNIVERSITY RESEARCH AND BUSINESS FOUNDATION
Seoul
KR
|
Family ID: |
60676807 |
Appl. No.: |
15/487549 |
Filed: |
April 14, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01J 3/0256 20130101;
G01J 3/0205 20130101; G01J 3/36 20130101; G01J 2003/1213 20130101;
G01J 3/2803 20130101; G02B 1/002 20130101; G01J 3/12 20130101 |
International
Class: |
G01J 3/12 20060101
G01J003/12; G01J 3/02 20060101 G01J003/02; G01J 3/28 20060101
G01J003/28; G02B 1/00 20060101 G02B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 24, 2016 |
KR |
10-2016-0079272 |
Claims
1. An optical unit device for selectively transmitting
electromagnetic waves of a wavelength range, the optical unit
device comprising: a material layer comprising slots, wherein a gap
between the slots has a distance such that the optical unit device
has a Q-factor of about 5 or more.
2. The optical unit device of claim 1, wherein the gap between the
slots has the distance such that the optical unit device has a
Q-factor of about 7 or more.
3. The optical unit device of claim 1, wherein the gap between the
slots has the distance such that the optical unit device has a
normalized transmittance of about 3 or more, and the normalized
transmittance is determined by dividing an intensity of
electromagnetic waves passing through the material layer comprising
the slots by an intensity of electromagnetic waves passing through
a single slot of another optical unit device without the material
layer.
4. The optical unit device of claim 1, wherein a resonance
wavelength of the optical unit device is .lamda., a refractive
index of a medium contacting an incident surface of the material
layer is n, and the distance of the gap between the slots is
greater than .lamda./(2.5.times.n).
5. The optical unit device of claim 4, wherein the distance of the
gap between the slots is less than .lamda./n.
6. The optical unit device of claim 1, wherein a resonance
wavelength of the optical unit device is determined based on the
gap between the slots.
7. The optical unit device of claim 1, wherein each of the slots
has a subwavelength size.
8. The optical unit device of claim 1, wherein the slots are
parallel to each other.
9. The optical unit device of claim 1, wherein each of the slots
has a length in a first direction and a width in a second direction
perpendicular to the first direction, and the slots are spaced
apart from each other in the second direction.
10. The optical unit device of claim 1, wherein the material layer
comprises two to five slots that are spaced apart from one another
by substantially a same gap and are parallel to one another.
11. The optical unit device of claim 1, wherein the material layer
is a conductive layer.
12. The optical unit device of claim 1, wherein the slots are light
source-less slots.
13. The optical unit device of claim 1, wherein the material layer
is sectioned into regions, and each of the regions comprises slots
parallel to one another.
14. The optical unit device of claim 1, wherein the material layer
is sectioned into regions, at least one of the regions comprises
first slots parallel to one another, at least another one of the
regions comprises second slots parallel to one another, and the
second slots are perpendicular to the first slots.
15. The optical unit device of claim 1, wherein the optical unit
device is configured to transmit electromagnetic waves of an
infrared ray (IR) range.
16. An optical unit device for selectively transmitting
electromagnetic waves of a wavelength range, the optical unit
device comprising: a material layer comprising slots, wherein a gap
between the slots has a distance greater than .lamda./(2.5.times.n)
where .lamda. refers to a resonance wavelength of the optical unit
device and n refers to a refractive index of a medium contacting an
incident surface of the material layer.
17. The optical unit device of claim 16, wherein the distance of
the gap between the slots is less than .lamda./n.
18. The optical unit device of claim 16, wherein the gap between
the slots has the distance such that the optical unit device has a
Q-factor of about 5 or more.
19. The optical unit device of claim 16, wherein the gap between
the slots has the distance such that the optical unit device has a
normalized transmittance of about 3 or more, and the normalized
transmittance is determined by dividing an intensity of
electromagnetic waves passing through the material layer comprising
slots by an intensity of electromagnetic waves passing through a
single slot of another optical unit device without the material
layer.
20. The optical unit device of claim 16, wherein the material layer
comprises two to five slots that are spaced apart from one another
by substantially a same gap and are parallel to one another.
21. The optical unit device of claim 16, wherein the slots are
light source-less slots.
22. A spectral device comprising: a first array device comprising
optical unit devices, each of the optical unit devices comprising
the optical unit device of claim 1, and at least two of the optical
unit devices being configured to transmit electromagnetic waves of
different wavelength ranges; and a second array device comprising
detectors configured to detect electromagnetic waves passing
through the first array device.
23. The spectral device of claim 22, wherein the first array device
comprises a first optical unit device and a second optical unit
device, the first optical unit device comprises a first slot and a
second slot, the second optical unit device comprises a third slot
and a fourth slot, and a gap between the first slot and the second
slot is different from a gap between the third slot and the fourth
slot.
24. The spectral device of claim 23, wherein either one or both of
the first slot and the second slot has a dimension different from a
dimension of either one or both of the third slot and the fourth
slot.
25. The spectral device of claim 23, wherein each of the first slot
and the second slot has a first length, and each of the third slot
and the fourth slot has a second length different from the first
length.
26. The spectral device of claim 22, wherein the first array device
comprises a first optical unit device and a second optical unit
device, and a number of slots included in the first optical unit
device is different from a number of slots included in the second
optical unit device.
27. The spectral device of claim 22, wherein the first array device
comprises a metasurface structure.
28. A spectrometer comprising the spectral device of claim 22.
29. An optical measurement apparatus for optically measuring
properties of an object, the optical measurement apparatus
comprising: a light source configured to irradiate light to the
object; an optical sensor comprising the spectral device of claim
22, and configured to detect light that is irradiated by the light
source and modulated by the object; and a signal processor
configured to process a signal that is measured by the optical
sensor.
30. The optical measurement apparatus of claim 29, wherein the
light source is configured to irradiate light of an infrared
range.
31. The optical measurement apparatus of claim 29, wherein at least
a part of the optical measurement apparatus constitutes a wearable
device.
32. The optical measurement apparatus of claim 29, wherein at least
a part of the optical measurement apparatus constitutes a mobile
device.
33. The spectral device of claim 22, further comprising: an
intermediate layer disposed between the first array device and the
second array device; a cover layer disposed on the first array
device; and a focusing element array disposed on the cover
layer.
34. An optical unit device for selectively transmitting
electromagnetic waves of a wavelength range, the optical unit
device comprising: a substrate; and a material layer comprising
slots, and disposed on the substrate, wherein a gap between the
slots has a distance corresponding to a Q-factor of the optical
unit device, a resonance wavelength of the optical unit device, and
a refractive index of the substrate.
35. The optical unit device of claim 34, wherein the gap between
the slots has the distance such that the Q-factor is about 5 or
more, and the distance of the gap between the slots is greater than
.lamda./(2.5.times.n) where .lamda. refers to the resonance
wavelength of the optical unit device and n refers to the
refractive index of the substrate.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Korean Patent
Application No. 10-2016-0079272, filed on Jun. 24, 2016, in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference in its entirety.
BACKGROUND
1. Field
[0002] Apparatuses consistent with exemplary embodiments relate to
an optical device and an optical apparatus, and more particularly,
to an optical device (optical element) including a slot and an
optical apparatus employing the optical device.
2. Description of the Related Art
[0003] Because a spectrometer according to a related art disperses
(splits) light by mainly using a prism or grating structure, a
space of about several centimeters to about tens of centimeters is
used for dispersing light. As the size of a spectrometer decreases,
a spectral resolving power may be lowered.
[0004] Technology capable of decreasing the size (miniaturizing) of
an optical apparatus such as a spectrometer and improving
performance thereof is being developed. A method or technology to
improve light efficiency and reduce the size of a unit area (unit
device) for light dispersing or imaging is demanded.
SUMMARY
[0005] Exemplary embodiments may address at least the above
problems and/or disadvantages and other disadvantages not described
above. Also, the exemplary embodiments are not required to overcome
the disadvantages described above, and may not overcome any of the
problems described above.
[0006] Exemplary embodiments provide optical devices (optical unit
devices) including a plurality of slots and designed to have
superior performance.
[0007] Exemplary embodiments provide optical devices (optical unit
devices) having small sizes and exhibiting superior
performance.
[0008] Exemplary embodiments provide optical devices (optical unit
devices) having relatively simple structures and having high
Q-factors and high transmittances.
[0009] Exemplary embodiments provide spectral devices (spectro
devices) including the optical devices.
[0010] Exemplary embodiments provide apparatuses (e.g.,
spectrometers) including the optical devices.
[0011] According to an aspect of an exemplary embodiment, there is
provided an optical unit device for selectively transmitting
electromagnetic waves of a wavelength range, the optical unit
device including a material layer including slots. A gap between
the slots has a distance such that the optical unit device has a
Q-factor of about 5 or more.
[0012] The gap between the slots may have the distance such that
the optical unit device has a Q-factor of about 7 or more.
[0013] The gap between the slots may have the distance such that
the optical unit device has a normalized transmittance of about 3
or more, and the normalized transmittance may be determined by
dividing an intensity of electromagnetic waves passing through the
material layer including the slots by an intensity of
electromagnetic waves passing through a single slot of another
optical unit device without the material layer.
[0014] A resonance wavelength of the optical unit device may be
.lamda., a refractive index of a medium contacting an incident
surface of the material layer may be n, and the distance of the gap
between the slots may be greater than .lamda./(2.5.times.n).
[0015] The distance of the gap between the slots may be less than
.lamda./n.
[0016] A resonance wavelength of the optical unit device may be
determined based on the gap between the slots.
[0017] Each of the slots may have a subwavelength size.
[0018] The slots may be parallel to each other.
[0019] Each of the slots may have a length in a first direction and
a width in a second direction perpendicular to the first direction,
and the slots may be spaced apart from each other in the second
direction.
[0020] The material layer may include two to five slots that are
spaced apart from one another by substantially a same gap and are
parallel to one another.
[0021] The material layer may be a conductive layer.
[0022] The slots may be light source-less slots.
[0023] The material layer may be sectioned into regions, and each
of the regions may include slots parallel to one another.
[0024] The material layer may be sectioned into regions, at least
one of the regions may include first slots parallel to one another,
at least another one of the regions may include second slots
parallel to one another, and the second slots may be perpendicular
to the first slots.
[0025] The optical unit device may be configured to transmit
electromagnetic waves of an infrared ray (IR) range.
[0026] According to an aspect of an exemplary embodiment, there is
provided an optical unit device for selectively transmitting
electromagnetic waves of a wavelength range, the optical unit
device including a material layer including slots. A gap between
the slots may have a distance greater than .lamda./(2.5.times.n)
where A refers to a resonance wavelength of the optical unit device
and n refers to a refractive index of a medium contacting an
incident surface of the material layer.
[0027] The distance of the gap between the slots may be less than
.lamda./n.
[0028] The gap between the slots may have the distance such that
the optical unit device has a Q-factor of about 5 or more.
[0029] The gap between the slots may have the distance such that
the optical unit device has a normalized transmittance of about 3
or more, and the normalized transmittance may be determined by
dividing an intensity of electromagnetic waves passing through the
material layer including slots by an intensity of electromagnetic
waves passing through a single slot of another optical unit device
without the material layer.
[0030] The material layer may include two to five slots that are
spaced apart from one another by substantially a same gap and are
parallel to one another.
[0031] The slots may be light source-less slots.
[0032] A spectral device may include a first array device including
optical unit devices, each of the optical unit devices including
the optical unit device, and at least two of the optical unit
devices being configured to transmit electromagnetic waves of
different wavelength ranges. The spectral device may further
include a second array device including detectors configured to
detect electromagnetic waves passing through the first array
device.
[0033] The first array device may include a first optical unit
device and a second optical unit device, the first optical unit
device may include a first slot and a second slot, the second
optical unit device may include a third slot and a fourth slot, and
a gap between the first slot and the second slot may be different
from a gap between the third slot and the fourth slot.
[0034] Either one or both of the first slot and the second slot may
have a dimension different from a dimension of either one or both
of the third slot and the fourth slot.
[0035] Each of the first slot and the second slot may have a first
length, and each of the third slot and the fourth slot may have a
second length different from the first length.
[0036] The first array device may include a first optical unit
device and a second optical unit device, and a number of slots
included in the first optical unit device may be different from a
number of slots included in the second optical unit device.
[0037] The first array device may include a metasurface
structure.
[0038] A spectrometer may include the spectral device.
[0039] An optical measurement apparatus for optically measuring
properties of an object, may include a light source configured to
irradiate light to the object, an optical sensor including the
spectral device, and configured to detect light that is irradiated
by the light source and modulated by the object, and a signal
processor configured to process a signal that is measured by the
optical sensor.
[0040] The light source may be configured to irradiate light of an
infrared range.
[0041] At least a part of the optical measurement apparatus may
constitute a wearable device.
[0042] At least a part of the optical measurement apparatus may
constitute a mobile device.
[0043] The spectral device may further include an intermediate
layer disposed between the first array device and the second array
device, a cover layer disposed on the first array device, and a
focusing element array disposed on the cover layer.
[0044] According to an aspect of an exemplary embodiment, there is
provided an optical unit device for selectively transmitting
electromagnetic waves of a wavelength range, the optical unit
device including a substrate, and a material layer including slots,
and disposed on the substrate. A gap between the slots has a
distance corresponding to a Q-factor of the optical unit device, a
resonance wavelength of the optical unit device, and a refractive
index of the substrate.
[0045] The gap between the slots may have the distance such that
the Q-factor is about 5 or more, and the distance of the gap
between the slots may be greater than .lamda./(2.5.times.n) where
.lamda. refers to the resonance wavelength of the optical unit
device and n refers to the refractive index of the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] The above and/or other aspects will become apparent and more
readily appreciated from the following description of exemplary
embodiments, taken in conjunction with the accompanying drawings in
which:
[0047] FIG. 1 is a perspective view of an optical unit device
according to a comparative example;
[0048] FIG. 2 is a graph of a transmission spectrum of
electromagnetic waves passing through a single slot of FIG. 1;
[0049] FIG. 3 is a perspective view of an optical unit device
according to an exemplary embodiment;
[0050] FIG. 4 is a graph of a transmission spectrum of
electromagnetic waves passing through the optical unit device
having a structure of FIG. 3;
[0051] FIG. 5 is a graph of a transmission spectrum of
electromagnetic waves passing through the optical unit device
having the structure of FIG. 3;
[0052] FIG. 6 is a graph showing a change in a Q-factor according
to a gap between slots in the optical unit device having the
structure of FIG. 3;
[0053] FIG. 7 is a graph showing a change in a peak value according
to the gap between the slots in the optical unit device having the
structure of FIG. 3;
[0054] FIG. 8 is a perspective view of an optical unit device
according to another exemplary embodiment;
[0055] FIG. 9 is a graph of a transmission spectrum of
electromagnetic waves passing through an optical unit device having
a structure of FIG. 8;
[0056] FIG. 10 is a perspective view of an optical unit device
according to another exemplary embodiment;
[0057] FIG. 11 is a perspective view of an optical unit device
according to another exemplary embodiment;
[0058] FIGS. 12 and 13 are graphs of a relationship between a gap
between two slots and a peak shift .lamda..sub.shift, according to
exemplary embodiments;
[0059] FIG. 14 is a graph of a relationship between a gap between
two slots and a peak shift .lamda..sub.shift in a mid-IR range, for
a 2-slot type optical unit device, according to an exemplary
embodiment;
[0060] FIG. 15 is a graph of a relationship between a gap between
two slots and a peak shift .lamda..sub.shift in a far-IR range, for
a 2-slot type optical unit device, according to an exemplary
embodiment;
[0061] FIGS. 16A, 16B, and 16C are images of simulation data for a
structure (2-slot structure) having two slots as illustrated in
FIG. 3, in which FIG. 16B shows a case in which the gap satisfies a
resonance requirement and FIGS. 16A and 16C show cases in which the
gap does not satisfy the resonance requirement;
[0062] FIG. 17 is a graph of an intensity profile of
electromagnetic waves passing through two slots, according to an
exemplary embodiment;
[0063] FIG. 18 is a set of graphs of intensity profiles in vertical
and horizontal directions of electromagnetic waves passing through
two slots of FIG. 17;
[0064] FIGS. 19A and 19B are plan views of two types of optical
unit devices according to exemplary embodiments;
[0065] FIG. 20 is a plan view of an optical unit device according
to another exemplary embodiment;
[0066] FIG. 21 is a plan view of an optical unit device according
to another exemplary embodiment;
[0067] FIG. 22 is a plan view of an optical unit device according
to another exemplary embodiment;
[0068] FIG. 23 is a plan view of an optical unit device according
to another exemplary embodiment;
[0069] FIG. 24 is a plan view of an optical device (array device)
including a plurality of optical unit devices, according to an
exemplary embodiment;
[0070] FIG. 25 is a plan view of an optical device (array device)
including a plurality of optical unit devices, according to another
exemplary embodiment;
[0071] FIG. 26 is a cross-sectional view of a spectral device
employing an optical device (optical unit device) according to an
exemplary embodiment;
[0072] FIG. 27 is a cross-sectional view of a spectral device
employing an optical device (optical unit device) according to
another exemplary embodiment;
[0073] FIG. 28 is a cross-sectional view of a spectral device
employing an optical device (optical unit device) according to
another exemplary embodiment;
[0074] FIG. 29 is a cross-sectional view of a spectral device
employing an optical device (optical unit device) according to
another exemplary embodiment;
[0075] FIG. 30 is a schematic block diagram of an optical
measurement apparatus employing a spectral device according to an
exemplary embodiment;
[0076] FIG. 31 is a diagram of an optical arrangement of a spectral
sensor module applicable to the optical measurement apparatus of
FIG. 30, according to an exemplary embodiment;
[0077] FIG. 32 is a diagram of an optical arrangement of a spectral
sensor module applicable to the optical measurement apparatus of
FIG. 30, according to another exemplary embodiment;
[0078] FIG. 33 is a diagram of a mobile device, to which an optical
measurement apparatus according to an exemplary embodiment is
applicable;
[0079] FIG. 34 is a diagram of a wearable device, to which an
optical measurement apparatus according to an exemplary embodiment
is applicable; and
[0080] FIG. 35 is a diagram of an optical measurement apparatus
according to another exemplary embodiment.
DETAILED DESCRIPTION
[0081] Example embodiments will now be described more fully with
reference to the accompanying drawings in which the example
embodiments are shown.
[0082] It will be understood that when an element is referred to as
being "connected" or "coupled" to another element, it can be
directly connected or coupled to the other element or intervening
elements may be present. In contrast, when an element is referred
to as being "directly connected" or "directly coupled" to another
element, there are no intervening elements present. As used herein
the term "and/or" includes any and all combinations of one or more
of the associated listed items.
[0083] It will be understood that, although the terms "first,"
"second," etc. may be used herein to describe various elements,
components, regions, layers and/or sections, these elements,
components, regions, layers and/or sections are not limited by
these terms. These terms are only used to distinguish one element,
component, region, layer or section from another element,
component, region, layer or section. Thus, a first element,
component, region, layer or section discussed below could be termed
a second element, component, region, layer or section without
departing from the teachings of example embodiments.
[0084] Spatially relative terms, such as "beneath," "below,"
"lower," "above," "upper" and the like, may be used herein for ease
of description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. It
will be understood that the spatially relative terms are intended
to encompass different orientations of the device in use or
operation in addition to the orientation depicted in the figures.
For example, if the device in the figures is turned over, elements
described as "below" or "beneath" other elements or features would
then be oriented "above" the other elements or features. Thus, the
exemplary term "below" can encompass both an orientation of above
and below. The device may be otherwise oriented (rotated 90 degrees
or at other orientations) and the spatially relative descriptors
used herein interpreted accordingly.
[0085] The terminology used herein is for the purpose of describing
exemplary embodiments only and is not intended to be limiting of
example embodiments. As used herein, the singular forms "a," "an"
and "the" are intended to include the plural forms as well, unless
the context clearly indicates otherwise. It will be further
understood that the terms "may include" and/or "comprising," when
used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or
groups thereof.
[0086] Example embodiments are described herein with reference to
cross-sectional illustrations that are schematic illustrations of
example embodiments. As such, variations from the shapes of the
illustrations as a result, for example, of manufacturing techniques
and/or tolerances, are to be expected. Thus, example embodiments
are not construed as limited to the shapes of regions illustrated
herein but are to include deviations in shapes that result, for
example, from manufacturing. For example, an implanted region
illustrated as a rectangle will, typically, have rounded or curved
features and/or a gradient of implant concentration at its edges
rather than a binary change from implanted to non-implanted region.
Likewise, a buried region formed by implantation may result in some
implantation in the region between the buried region and the
surface through which the implantation takes place. Thus, the
regions illustrated in the figures are schematic in nature and
their shapes are not intended to illustrate the actual shape of a
region of a device and are not intended to limit the scope of
example embodiments.
[0087] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which example
embodiments belong. It will be further understood that terms, such
as those defined in commonly-used dictionaries, are interpreted as
having a meaning that is consistent with their meaning in the
context of the relevant art and will not be interpreted in an
idealized or overly formal sense unless expressly so defined
herein.
[0088] Reference will now be made in detail to an optical device
including a slot and an optical apparatus employing the optical
device, according to exemplary embodiments, examples of which are
illustrated in the accompanying drawings. In the drawings, the
width and thicknesses of layers and regions are exaggerated for
clarity of the specification and for convenience of explanation.
Like reference numerals refer to like elements throughout.
[0089] FIG. 1 is a perspective view of an optical unit device D1
according to a comparative example.
[0090] Referring to FIG. 1, the optical unit device D1 according to
a comparative example may include a conductive material layer M1
where a single slit S1 is formed. The single slot S1 may have a
length L, a width W, and a thickness T. The conductive material
layer M1 may be arranged on a substrate SUB1. The substrate SUB1
may be, for example, a glass substrate.
[0091] Electromagnetic waves of a wavelength range may pass through
the single slot S1 formed in the conductive material layer M1. In
this state, a resonance frequency may be defined by the single slot
S1 in the optical unit device D1 according to a comparative
example. In other words, a resonance frequency may be determined by
the length L, the width W, and the thickness T of the single slot
S1. A resonance wavelength may correspond to the resonance
frequency. The resonance wavelength may be greater than the length
L of the single slot S1. In a graph showing transmittance of
electromagnetic waves passing through the single slot S1, a
wavelength corresponding to a peak point may correspond to the
resonance wavelength.
[0092] FIG. 2 is a graph of a transmission spectrum of
electromagnetic waves passing through the single slot S1 of FIG. 1.
In this state, the length L, the width W, and the thickness T of
the single slot S1 are 550 nm, 100 nm, and 300 nm, respectively.
The conductive material layer M1 is an Ag layer and the substrate
SUB1 is a glass substrate. A transmission spectrum is measured by
irradiating electromagnetic waves from a side where the substrate
SUB1 is formed toward the conductive material layer M1. In FIG. 2,
a Y-axis value, that is, <S>/<S>.sub.air, denotes
normalized transmittance. "<S>" denotes a pointing vector of
the electromagnetic waves passing through the single slot S1 when
the conductive material layer M1 exists. "<S>.sub.air"
denotes a pointing vector of the electromagnetic waves passing
through a single slot region (i.e., S1 region) when the conductive
material layer M1 does not exist. As a value of
"<S>/<S>.sub.air" increases, transmittance
increases.
[0093] Referring to FIG. 2, a major wavelength of the
electromagnetic waves passing through the single slot S1 is about
1522 nm, a peak height (peak value) is about 2.5, and a Q-factor is
about 3.4. The Q-factor may be defined by Mathematical Expression
1.
Q .ident. .omega. 0 .DELTA. .omega. = 1 .lamda. 0 1 1 .lamda. 1 - 1
.lamda. 2 = .lamda. 1 .lamda. 2 .lamda. 0 ( .lamda. 2 - .lamda. 1 )
[ Mathematical Expression 1 ] ##EQU00001##
[0094] In Mathematical Expression 1, the Q-factor Q may be defined
to be a ratio between the resonance frequency .omega..sub.0 (center
frequency) and a bandwidth .DELTA..omega.. Also, the Q-factor Q may
be defined by a relation between a resonance wavelength
.lamda..sub.0, and .lamda..sub.1 and .lamda..sub.2. ".lamda..sub.1"
and ".lamda..sub.2" respectively denote a lower wavelength
.lamda..sub.1 and an upper wavelength .lamda..sub.2 at a point
corresponding to 1/2 of the peak value (refer to FIG. 2). The
Q-factor Q with respect to the graph of FIG. 2 may be calculated by
using Mathematical Expression 1.
[0095] Table 1 below is a summary of values obtained from FIG.
2.
TABLE-US-00001 TABLE 1 Comparative Example (Structure of FIG. 1)
Items Peak Position (nm) Peak Value Q-factor Values 1522 2.5
3.4
[0096] Referring to FIG. 2 and the result of Table 1, when the
single slot S1 is used as in the comparative example, the Q-factor
is as low as about 3.4 and the peak value corresponding to the
transmittance (normalized transmittance) is as low as about 2.5. In
other words, in the case of using the signal slot S1 as in the
comparative example of FIG. 1, although the resonance frequency can
be defined by the single slot S1, there is a limit in securing the
Q-factor and the transmittance.
[0097] FIG. 3 is a perspective view of an optical unit device D10
according to an exemplary embodiment.
[0098] Referring to FIG. 3, the optical unit device D10 according
to the exemplary embodiment may include a conductive material layer
M10 where a plurality of slots S11 and S12 are formed. A case of
using two slots, that is, a first slot S11 and a second slot S12,
is illustrated and described. Each of the two slots S11 and S12 may
have a length L, a width W, and a thickness T. The slots S11 and
S12 may be a "light source-less slot," that is, a slot having no
light source. The conductive material layer M10 may be provided on
a substrate SUB10. The substrate SUB 10 may include a transparent
material with respect to electromagnetic waves of a wavelength
range of interest. For example, the substrate SUB 10 may be a glass
substrate. However, the material of the substrate SUB 10 is not
limited to glass and may be variously changed. For example, the
substrate SUB 10 may include a dielectric such as a silicon oxide
or, in some cases, semiconductor such as silicon.
[0099] In the exemplary embodiment, a gap d10 between the slots S11
and S12 may be controlled to satisfy a requirement (condition) of
interaction between electromagnetic waves passing through the first
slot S11 and electromagnetic waves passing through the second slot
S12. In other words, the gap d10 between the slots S11 and S12 may
be controlled to satisfy a requirement of coherence of the
electromagnetic waves passing through the first slot S11 and the
electromagnetic waves passing through the second slot S12. As a
result, the Q-factor of the optical unit device D10 may be much
improved and transmittance may also be improved. For example, the
Q-factor of the optical unit device D10 may be about 5 or more. The
Q-factor of the optical unit device D10 may be about 7 or more or
about 8 or more. The normalized transmittance of the optical unit
device D10 may be about 3 or more. The normalized transmittance of
the optical unit device D10 may be about 5 or more. The normalized
transmittance may be defined to be a value, that is,
<S>/<S>.sub.air, obtained by dividing intensity of
electromagnetic waves passing through the conductive material layer
M10 having the slots S11 and S12 by intensity of electromagnetic
waves passing through a single slot area (slot area corresponding
to the slot S11) in a state of having no conductive material layer
M10.
[0100] FIG. 4 is a graph of a transmission spectrum of
electromagnetic waves passing through the optical unit device D10
having the structure of FIG. 3. In this state, the length L, the
width W, and the thickness T of each of the two slots S11 and S12
may be about 550 nm, about 100 nm, and about 300 nm, respectively.
The conductive material layer M10 is an Ag layer, and the substrate
SUB 10 is a glass substrate. While changing the gap d10 between the
two slots S11 and S12 from about 500 nm to about 750 nm by units of
about 50 nm, a transmission spectrum is measured. The transmission
spectrum is measured by irradiating electromagnetic waves from a
side where the substrate SUB 10 is formed toward the conductive
material layer M10. In this state, the substrate SUB 10 may be a
sort of a "medium" provided on an incident surface of the
conductive material layer M10. A refractive index n of the medium
(substrate) SUB 10 is about 1.44.
[0101] Referring to FIG. 4, when the two slots S11 and S12 are
used, the Q-factor and the transmittance may be much increased by
about 300%-about 400%, compared to a case of using a single slot as
illustrated in FIG. 2. Also, the Q-factor and the resonance
wavelength are changed according to the gap d10 between the two
slots S11 and S12. Accordingly, the optical unit device D10 may be
appropriately designed and used to match the purpose thereof.
[0102] FIG. 5 is a graph of a transmission spectrum of
electromagnetic waves passing through the optical unit device D10
having the structure of FIG. 3. While changing the gap d10 between
the two slots S11 and S12 from about 250 nm to about 450 nm by
units of about 50 nm, a transmission spectrum is measured. The
dimensions of the slots S11 and S12 and the constituent materials
of the substrate SUB10 and the conductive material layer M10 are
the same as those described in FIG. 4.
[0103] Referring to FIG. 5, when the gap d10 between the two slots
S11 and S12 is about 450 nm, the Q-factor is expected to be about
5.9. When the gap d10 is about 400 nm, the Q-factor is expected to
be about 5.2. When the gap d10 is about 350 nm or less, the
Q-factor is small or measurement in a wavelength range of interest
is impossible. In other words, when the gap d10 is too small, it
may be difficult to obtain superior performance of the optical unit
device D10.
[0104] According to the results of FIGS. 4 and 5, when the gap d10
between the two slots S11 and S12 satisfies requirements
(conditions), a high Q-factor and a high transmittance may be
obtained. When the gap d10 is too small or too large, it may be
difficult to obtain superior performance.
[0105] Table 2 below is a summary of values obtained from FIGS. 4
and 5.
TABLE-US-00002 TABLE 2 2-Slot Structure (Structure of FIG. 3) Gap
d10 (nm) Peak Position (nm) Peak Value Q-factor 250 1406 5.1 300
1418 6.0 350 1431 7.0 400 1449 8.1 5.2 (expected) 450 1467 9.0 5.9
(expected) 500 1486 9.5 6.9 550 1504 9.6 7.6 600 1522 9.1 8.2 650
1535 8.2 8.3 700 1547 7.1 8.1 750 1559 6.0 7.6 800 1571 5.0 6.9 850
1571 4.2 5.9 900 1578 3.6 5.2 950 1571 3.1 5.0
[0106] FIGS. 6 and 7 are graphs showing changes in the Q-factor and
a peak value according to a gap between the slots S11 and S12 in
the optical unit device D10 having the structure of FIG. 3,
obtained from Table 2.
[0107] Referring to FIG. 6, a Q-factor of about 5 or more may be
obtained in a range of about 500 nm to 950 nm. A high Q-factor of
about 7 or more (about 6.9 to about 8.3) may be obtained in a range
of about 500 nm to 800 nm.
[0108] Referring to FIG. 7, the peak value becomes maximum at about
550 nm and thereabout. A peak value of about 5 or more may be
obtained in a range of about 250 nm to about 800 nm. A high peak
value may be obtained in a range of about 400 nm to about 750 nm.
The peak value may correspond to the above-defined normalized
transmittance. Although a peak value is obtained to a degree in a
region of about 350 nm or less, it may be difficult to measure and
obtain the Q-factor (refer to FIG. 5).
[0109] Referring to Table 2 and the results of FIGS. 6 and 7
obtained from Table 2, in the exemplary embodiment, the gap d10 of
the two slots S11 and S12 may be determined between about 400 nm
and about 950 nm. To secure a Q-factor of about 7 or more
(including 6.9) and a normalized transmittance (peak value) of
about 5 or more, the gap d10 of the two slots S11 and S12 may be
determined between about 500 nm to about 800 nm. However, an
appropriate range of the gap d10 may vary according to the
dimensions (length/width/thickness) of the slots S11 and S12 and
the constituent material of the conductive material layer M10.
Also, the appropriate range of the gap d10 may vary according to
the constituent material (refractive index) of the substrate SUB 10
and a wavelength range of the electromagnetic waves in use.
[0110] According to the exemplary embodiment, assuming that a
resonance wavelength of the optical unit device D10 is A and a
refractive index of a medium (substrate) contacting the incident
surface of the conductive material layer M10 is n, the gap d10
between the slots S11 and S12 may be greater than
.lamda./(2.5.times.n). The gap d10 in a range of about 400 nm to
about 950 nm in Table 2 satisfies the above requirements. In this
state, the resonance wavelength .lamda. corresponds to a peak
position, and the refractive index n of the medium is about 1.44.
Also, the gap d10 between the slots S11 and S12 may be less than
.lamda./n. The gap d10 in a range of about 400 nm to about 950 nm
in Table 2 satisfies the above requirements. Accordingly, the gap
d10 between the slots S11 and S12 may be greater than
.lamda./(2.5.times.n) and less than .lamda./n.
[0111] FIG. 8 is a perspective view of an optical unit device D20
according to another exemplary embodiment.
[0112] Referring to FIG. 8, the optical unit device D20 according
to the exemplary embodiment may include a conductive material layer
M20 where a plurality of slots S21, S22, and S23 are formed. A case
of using three slots, that is, a first slot S21, a second slot S22,
and a third slot S23 is illustrated and described. The slots S21,
S22, and S23 may be light source-less slots. The conductive
material layer M20 may be arranged on a substrate SUB 20. The
substrate SUB 20 may be the same as the substrate SUB 10 of FIG.
3.
[0113] In the exemplary embodiment, a gap d21 between the first
slot S21 and the second slot S22 and a gap d22 between the second
slot S22 and the third slot S23 may be appropriately selected. In
other words, the gaps d21 and d22 may be controlled to satisfy
requirements of interaction and/or coherence among electromagnetic
waves passing through the slots S21, S22, and S23. As a result, the
Q-factor and the transmittance of the optical unit device D20 may
be much improved. For example, the Q-factor of the optical unit
device D10 may be about 5 or more. The Q-factor of the optical unit
device D10 may be about 8 more or about 10 or more. The normalized
transmittance of the optical unit device D10 may be about 3 or
more. The normalized transmittance of the optical unit device D10
may be about 8 more or about 11 or more. The normalized
transmittance may be defined to be a value, that is,
<S>/<S>.sub.air, obtained by dividing intensity of
electromagnetic waves passing through the conductive material layer
M20 having the slots S21, S22, and S23 by intensity of
electromagnetic waves passing through a single slot area (slot
corresponding to the slot S22) in a state of having no conductive
material layer M20. When three slots, that is, the slots S21, S22,
and S23 of FIG. 8, are used, a relatively high Q-factor and a
relative high transmittance may be obtained compared to a case of
using two slots, that is, the slots S11 and S12, as illustrated in
FIG. 3.
[0114] FIG. 9 is a graph of a transmission spectrum of
electromagnetic waves passing through the optical unit device D20
having a structure of FIG. 8. In this state, the length L, the
width W, and the thickness T of each of the slots S21, S22, and S23
are 550 nm, 100 nm, and 300 nm, respectively. The conductive
material layer M20 is an Ag layer, and the substrate SUB 20 is a
glass substrate. A transmission spectrum is measured by changing
the gas d21 and d22 between the slots S21, S22, and S23 from about
550 nm to about 850 nm by units of 50 nm. In this state, the gaps
d21 and d22 are the same. The substrate SUB 20 may be a sort of a
"medium" provided on an incident surface of the conductive material
layer M20, and the refractive index n of the medium (substrate)
SUB20, is about 1.44.
[0115] Referring to FIG. 9, when three slots, that is, the slots
S21, S22, and S23, are used, the Q-factor is improved by about 300%
or more and the transmittance is improved by about 700% or more,
compared to the case of using a single slot of FIG. 2. Also, when
three slots, that is, the slots S21, S22, and S23, are used, the
Q-factor is improved by about 25% and the transmittance is improved
by about 60%, compared to the case of using two slots of FIG. 4.
Accordingly, as the number of slots increases, the Q-factor and the
transmittance are further improved due to the gap control between
slots. Also, the Q-factor and the resonance wavelength are changed
according to the gaps d21 and d22 between the slots S21, S22, and
S23. Accordingly, the optical unit device D20 may be appropriately
designed and used to match the purpose thereof.
[0116] Table 3 below is a summary of values obtained from FIG.
9.
TABLE-US-00003 TABLE 3 3-Slot Structure (Structure of FIG. 8) Gap
(d21, d22) (nm) Peak Position (nm) Peak Value Q-factor 550 1491
15.2 8.6 600 1504 16.1 9.3 650 1522 16.5 10.3 700 1541 15.8 10.4
750 1559 13.9 10.5 800 1578 11.4 10.2 850 1590 8.7 9.2
[0117] Referring to FIGS. 8 and 9 and the result of Table 3, a
Q-factor of about 8 or more may be obtained in a range from about
550 nm to about 850 nm. A high Q-factor of about 10 or more may be
obtained in a range from about 650 nm to 800 nm. Also, a peak value
of about 8 or more may be obtained in a range from about 550 nm to
about 850 nm. A peak value of about 11 or more may be obtained in a
range from about 550 nm to about 800 nm. The peak value may
correspond to the above-defined normalized transmittance. In the
exemplary embodiment, to simultaneously obtain a Q-factor of about
10 or more and a peak value of about 11 or more, the gaps d21 and
d22 between the slots S21, S22, and S23 may be determined in a
range from about 650 nm to about 800 nm. However, appropriate
ranges of the gaps d21 and d22 may vary according to the dimensions
(length/width/thickness) of the slots S21, S22, and S23, the
constituent material of the conductive material layer M20, the
constituent material of the substrate SUB20, and the wavelength
range of electromagnetic waves in use.
[0118] According to the exemplary embodiment, assuming that a
resonance wavelength of the optical unit device D20 is .lamda. and
the refractive index of a medium (substrate) provided on
(contacting) the incident surface of the conductive material layer
M20 is n, the gaps d21 and d22 between the slots S21, S22, and S23
may be greater than .lamda./(2.5.times.n). Also, the gaps d21 and
d22 between the slots S21, S22, and S23 may be less than .lamda./n.
The gaps d21 and d22 in a range of about 550 nm to about 850 nm in
Table 3 satisfy the above requirements.
[0119] In the exemplary embodiments, metal or a metallic material
may be used as the materials of the conductive material layers M10
and M20. For example, any one or any combination of Ag, Cu, Al, Ni,
Fe, Co, Zn, Ti, Ru, Rh, Pd, Pt, Os, Ir, and Au, or an alloy
including any one thereof, may be used as the materials of the
conductive material layers M10 and M20. Also, two-dimensional
materials exhibiting superior conductivity, such as, graphene, or a
conductive compound, for example, a conductive oxide, may be used
as the materials of the conductive material layers M10 and M20.
[0120] Each of the slots S11, S12, S21, S22, and S23 may have a
hexahedral shape having the length L, the width W, and the
thickness T, or a similar shape thereto. The length L may be less
than the resonance wavelength .lamda.. In this case, the slots S11,
S12, S21, S22, and S23 may have a subwavelength size. In other
words, the slots S11, S12, S21, S22, and S23 may have a
subwavelength length. The width W may be less than the length L,
and the thickness T may also be less than the length L. For
example, the length L may be about 100 nm to about several
micrometers (.mu.m). The length L may be about 100 nm to about 3
.mu.m, or about 100 nm to about 1500 nm. An appropriate length L
may vary according to the wavelength range of interest, that is, an
intended resonance wavelength. When the length L is equal to or
less than about 1500 nm, the width W may be equal to or less than
about 600 nm or equal to or less than about 300 nm and the
thickness T may be equal to or less than about 1000 nm or equal to
or less than about 700 nm. However, when the range of the
appropriate length L varies, the ranges of an appropriate width W
and an appropriate thickness T may vary accordingly. The gap
between two adjacent slots may be determined to be several
micrometers (.mu.m) or less.
[0121] The conductive material layers M10 and M20 including the
slots S11, S12, S21, S22, and S23 may generate surface plasmon by
the electromagnetic waves incident thereon. In this regard, the
conductive material layers M10 and M20 or the slots S11, S12, S21,
S22, and S23 may be referred to as the "plasmonic structure." When
the slots S11, S12, S21, S22, and S23 have a nanoscale, it may be
called a nanoantenna.
[0122] Slits used in a general slit array method have optically
different properties from the slots used in the exemplary
embodiments. A slit has a length much longer than a resonance
wavelength, and the resonance wavelength (resonance frequency) may
not be defined by using a single slit. To define the resonance
wavelength (resonance frequency) using a slit array, many slits,
for example, about ten slits, are used. A resonance mode is
generated not from each slit, but from a slit array. Accordingly, a
relatively large space may be used to define a resonance wavelength
using a slit array. When grooves are used, many grooves
constituting a groove array may be used to define the resonance
wavelength like the slits. Also, when a slit array or a groove
array is in use, electromagnetic waves pass through one slit or
hole located at the center and thus transmission efficiency may be
lowered.
[0123] In contrast, the slot used in the exemplary embodiments may
have a length shorter than the resonance wavelength, and the
resonance wavelength (resonance frequency) may be defined by using
one slot. Also, when a plurality of slots are used and the gap
between the slots are controlled, electromagnetic waves pass
through each slot and the electromagnetic waves having passed the
slots are reinforced through interaction, and thus a high Q-factor
and a high transmission efficiency may be obtained. Also, because
slots of about six or less or about four or less are included in a
single unit device, a unit device (spectral unit device) of a small
size may be easily implemented. Accordingly, a unit device
(spectral unit device) having a size smaller than a pixel used in a
general pixel array may be implemented. When the unit device
according to the exemplary embodiment is used, a compact/ultra
compact optical device, for example, a spectrometer, may be easily
implemented.
[0124] FIG. 10 is a perspective view of an optical unit device D30
according to another exemplary embodiment.
[0125] Referring to FIG. 10, the optical unit device D30 may
include a conductive material layer M30 where four slots S31, S32,
S33, and S34 are formed. A first slot S31 may be spaced apart from
the second slot S32 by a first gap d31. The second slot S32 may be
spaced apart from the third slot S33 by a second gap d32. The third
slot S33 may be spaced apart from the fourth slot S34 by a third
gap d33. The first to fourth slots S31, S32, S33, and S34 may be
arranged parallel to one another by substantially the same gap.
However, this is an example and the arrangement of the slots S31,
S32, S33, and S34 may be variously changed. The conductive material
layer M30 may be arranged on a substrate SUB30. The materials of
the conductive material layer M30 and the substrate SUB30 may be
the same as or similar to those described in FIG. 3.
[0126] FIG. 11 is a perspective view of an optical unit device D40
according to another exemplary embodiment.
[0127] Referring to FIG. 11, the optical unit device D40 may
include a conductive material layer M40 where five slots S41, S42,
S43, S44, and S45 are formed. The first slot S41 may be spaced
apart from the second slot S42 by a first gap d41. The second slot
S42 may be spaced apart from the third slot S43 by a second gap
d42. The third slot S43 may be spaced apart from the fourth slot
S44 by a third gap d43. The fourth slot S44 may be spaced apart
from the fifth slot S45 by a fourth gap d44. The conductive
material layer M40 may be arranged on a substrate SUB40.
[0128] Although a case in which the optical unit device includes
five or less number of slots, in some cases, the optical unit
device may include six or more number of slots.
[0129] A method of setting a range of the gap d10 in the structure
(2-slot structure) including the two slots S11 and S12 as
illustrated in FIG. 3 is exemplarily described as follows.
[0130] When the length (length of a long side) and the width
(length of a short side) of each of the slots S11 and S12 are L and
W, respectively, and a refractive index of the substrate SUB 10
(medium) is n, a range of the gap d10 satisfying the requirements
of the Q-factor and transmittance of the optical unit device D10
may be expressed by Mathematical Expression 2 below. The thickness
(height) of each of the slots S11 and S12 is assumed to be about
300 nm.
d = ( 1.55 .times. L n - W ) .about. ( 2.1 .times. L n - W ) [
Mathematical Expression 2 ] ##EQU00002##
[0131] In the 2-slot structure including two slots, when a gap d
(d10 of FIG. 3) between two slots satisfies Mathematical Expression
2, the optical unit device D10 may have high Q-factor and high
transmittance.
[0132] In the structure (2-slot structure) including the two slots
S11 and S12 as illustrated in FIG. 3, a relation may be established
between the gap d10 and the resonance wavelength A. For example,
when the wavelength range of interest is a near-infrared (IR) range
around 1.5 .mu.m (1500 nm), Mathematical Expression 3 may be
established between the resonance wavelength A and the gap d10.
.lamda. shift .lamda. single .apprxeq. 0.15 n 2 ( gap .lamda.
single - 0.4 ) [ Mathematical Expression 3 ] ##EQU00003##
[0133] In Mathematical Expression 3, ".lamda..sub.single " denotes
a resonance wavelength when one slot, for example, the slot S11,
exists, and ".lamda..sub.shift" denotes an amount of a change in
the resonance wavelength when the two slots S11 and S12 are used.
Accordingly, the resonance wavelength A when the two slots S11 and
S12 are used may be ".lamda..sub.single+.lamda..sub.shift." "n"
denotes a refractive index of the substrate SUB10 (medium). When
the dimensions (length/width/thickness) of a slot, for example, the
slot S11, are determined, .lamda..sub.single may be determined
accordingly. In a state in which the refractive index n is
determined, .lamda..sub.shift may vary according to the gap.
Accordingly, the resonance wavelength .lamda. according to the gap
may be obtained.
[0134] FIGS. 12 and 13 are graphs of a relationship between a gap
between two slots and a peak shift (.lamda..sub.shift) when the
refractive index n of the medium (substrate) is 1.44 and 1.22,
respectively, according to exemplary embodiments. FIGS. 12 and 13
respectively include relations when the refractive index n is 1.44
and 1.22. Referring to FIGS. 12 and 13, the gap in the wavelength
range of interest may be proportional to .lamda..sub.shift. In both
of FIGS. 12 and 13, the wavelength range of interest is a near-IR
range around 1.5 .mu.m (1500 nm).
[0135] FIG. 14 is a graph of a relationship between a gap between
two slots and a peak shift (.lamda..sub.shift) in a mid-IR range,
for a 2-slot type optical unit device, according to an exemplary
embodiment. The range of a wavelength is about 3-5 .mu.m, and the
refractive index n of the medium (substrate) is 1.44.
[0136] FIG. 15 is a graph of a relationship between a gap between
two slots and a peak shift (.lamda..sub.shift) in a far-IR range,
for a 2-slot type optical unit device. The range of a wavelength is
about 7-10 .mu.m, and the refractive index n of the medium
(substrate) is 1.44.
[0137] As illustrated in FIGS. 14 and 15, when a wavelength range
varies, the relation between the gap and .lamda..sub.shift, that
is, the relation between the gap and the resonance wavelength
.lamda., may vary. However, in FIGS. 14 and 15, as the gap
increases, .lamda..sub.shift increases as well.
[0138] FIGS. 16A, 16B, and 16C are images of simulation data for a
structure (2-slot structure) having two slots as illustrated in
FIG. 3, in which FIG. 16B shows a case in which the gap satisfies a
resonance requirement and FIGS. 16A and 16C show cases in which the
gap does not satisfy the resonance requirement. The resonance
requirement denotes that the electromagnetic wave passing through
two slots are reinforced by interaction and/or coherence.
[0139] When the gap between two slots satisfies the resonance
requirement as in FIG. 16B, the Q-factor and the transmittance may
be much improved. In this state, the gap between two slots is about
650 nm. When the gap between two slots does not satisfy the
resonance requirement as in FIGS. 16A and 16C, it is difficult to
obtain a high Q-factor and a high transmittance.
[0140] FIG. 17 is a graph of an intensity profile of
electromagnetic waves passing through two slots, according to an
exemplary embodiment. The gap between two slots is about 650 nm,
the resonance wavelength is about 1535 nm, and the refractive index
of a substrate is about 1.44.
[0141] FIG. 18 is a set of graphs of intensity profiles in vertical
and horizontal directions of electromagnetic waves passing through
two slots of FIG. 17. In FIG. 18, a graph (A) shows a vertical
profile along a center perpendicular line, a graph (B) shows a
horizontal profile at a distance of 400 nm from a slot, and a graph
(C) shows a horizontal profile at a distance of 1000 nm from the
slot. According to the graph (A) of FIG. 18, intensity of
transmissive electromagnetic waves at a distance between about
100-1000 nm, for example, a distance between about 150-850 nm, from
a material layer where a plurality of slots are formed is high.
This information may be used to determine, for example, the
position of a detector for detecting transmissive electromagnetic
waves. According to the graphs (B) and (C) of FIG. 18, the
horizontal profile varies according to the distance from a slot. A
profile of transmissive electromagnetic waves may vary according to
the wavelength condition, the number and size of slots, or the gap
between slots.
[0142] FIGS. 19A and 19B are plan views of two types of optical
unit devices according to exemplary embodiments.
[0143] FIG. 19A illustrates a case in which a plurality of slots
S10a and S10b extending in a first direction, for example, an
X-axis direction, are formed in a conductive material layer M11.
FIG. 19B illustrates a case in which a plurality of slots S20a and
S20b extending in a second direction, for example, a Y-axis
direction, are formed in the conductive material layer M11. The
slots S10a and S10b of FIG. 19A may relatively well transmit
electromagnetic waves polarized in the Y-axis direction compared to
electromagnetic waves polarized in the X-axis direction. In
contrast, the slots S20a and S20b of FIG. 19B may relatively well
transmit electromagnetic waves polarized in the X-axis direction
compared to the electromagnetic waves polarized in the Y-axis
direction. In other words, the optical unit device may have
polarization dependency according to the direction in which slots
are formed (extended).
[0144] According to an exemplary embodiment, the structure of FIG.
19A or 19B may be applied to one optical unit device.
[0145] According to another exemplary embodiment, the structures of
FIGS. 19A and 19B may be mixedly applied to one optical unit
device, and examples thereof are illustrated in FIGS. 20 to 22.
[0146] FIG. 20 is a plan view of an optical unit device D15
according to another exemplary embodiment.
[0147] Referring to FIG. 20, the optical unit device D15 may
include a conductive material layer M15 and a plurality of slots
S10a, S10b, S20a, and S20b formed in the conductive material layer
M15. The slots S10a, S10b, S20a, and S20b may include the first
slots S10a and S10b extending in the X-axis direction and the
second slots S20a and S20b extending in the Y-axis direction. The
first slots S10a and S10b may correspond to the slots S10a and S10b
of FIG. 19A, and the second slots S20a and S20b may correspond to
the slots S20a and S20b of FIG. 19B. The second slots S20a and S20b
may be arranged perpendicular to the first slots S10a and S10b. As
such, when both of the first slots S10a and S10b extending in the
X-axis direction and the second slots S20a and S20b extending in
the Y-axis direction are included in the optical unit device D15,
an electromagnetic wave component polarized in the X-axis direction
and an electromagnetic wave component polarized in the Y-axis
direction are effectively transmitted so that light efficiency may
be improved.
[0148] Superior optical coupling properties may exist between the
first slots S10a and S10b, and similarly, superior optical coupling
properties may exist between the second slots S20a and S20b.
Interaction between the first slots S10a and S10b and the second
slots S20a and S20b may be relatively very weak. Accordingly, even
when the first slots S10a and S10b and the second slots S20a and
S20b exist together, the first slots S10a and S10b may improve
transmission properties and the second slots S20a and S20b may
improve transmission properties, whereas the interaction between
the first slots S10a and S10b and the second slots S20a and S20b
may be hardly generated.
[0149] FIG. 21 is a plan view of an optical unit device D25
according to another exemplary embodiment.
[0150] Referring to FIG. 21, the optical unit device D25 may
include a conductive material layer M25. The conductive material
layer M25 may be sectioned (divided) into a plurality of regions.
Each of the regions may include a plurality of slots S10a and S10b
parallel to each other, or a plurality of slots S20a and S20b
parallel to each other. For example, at least one of the regions
may include the first slots S10a and S10b extending in the X-axis
direction, and at least another of the regions may include the
second slots S20a and S20b extending in the Y-axis direction.
Although the conductive material layer M25 is equally divided into
four regions and the first slots S10a and S10b and the second slots
S20a and S20b are alternatively arranged clockwise from the upper
left region, this is an example and the arrangement method may be
variously changed.
[0151] FIG. 22 is a plan view of an optical unit device D35
according to another exemplary embodiment.
[0152] Referring to FIG. 22, the optical unit device D35 may
include a conductive material layer M35. The conductive material
layer M35 may be sectioned (divided) into a plurality of regions.
Each of the regions may include a plurality of slots S10a and S10b
parallel to each other, or a plurality of slots S20a and S20b
parallel to each other. For example, the conductive material layer
M35 may be sectioned into upper, lower, left, and right regions
with respect to a center portion thereof, and the slots S10a and
S10b or S20a and S20b may be arranged in the respective upper,
lower, left, and right regions. In a detailed example, the first
slots S10a and S10b may be arranged in each of the left and right
regions with respect to the center portion, and the second slots
S20a and S20b may be arranged in each of the upper and lower
regions with respect to the center portion. In this case, the first
slots S10a and S10b and the second slots S20a and S20b may
substantially have a cross shape. Alternatively, the first slots
S10a and S10b may be arranged in each of the upper and lower
regions with respect to the center portion of the conductive
material layer M35, the second slots S20a and S20b may be arranged
in each of the left and right regions with respect to the center
portion of the conductive material layer M35.
[0153] FIG. 23 is a plan view of an optical unit device D45
according to another exemplary embodiment.
[0154] Referring to FIG. 23, the optical unit device D45 may be
sectioned (divided) into a plurality of regions. Each of the
regions may include a plurality of slots S10a and S10b arranged in
the same direction. For example, each of the regions may include
the first slots S10a and S10b. When incident electromagnetic waves
are polarized in one direction, the optical unit device D45 of FIG.
23 may be used. For example, when the incident electromagnetic
waves are polarized in the Y-axis direction, the optical unit
device D45 of FIG. 23 may be used. When the incident
electromagnetic waves are polarized in the X-axis direction, the
second slots S20a and S20b of FIG. 19 instead of the first slots
S10a and S10b may be used.
[0155] The optical unit devices according to the above-described
exemplary embodiments may be arranged in a plural number in two
dimensions. In other words, a plurality of optical unit devices may
be arrayed, and examples thereof are illustrated in FIGS. 24 and
25.
[0156] FIG. 24 is a plan view of an optical device (array device)
D100 including a plurality of optical unit devices, according to an
exemplary embodiment.
[0157] Referring to FIG. 24, the optical device (array device) D100
may include a plurality of unit device regions DR11, DR12, DR13,
DR14, DR15, and DR16 arranged in two dimensions. Each of the unit
device regions DR11-DR16 may be configured to transmit
electromagnetic waves of a wavelength range. The unit device
regions DR11-DR16 may respectively include a plurality of slots
S11a and S11b, S12a and S12b, S13a and S13b, S14a and S14b, S15a
and S15b, and S16a and S16b. The unit device regions DR11-DR16 may
include the first unit device region DR11 and the second unit
device region DR12. The slots S11a and S11b constituting the first
unit device region DR11 and the slots S12a and S12b constituting
the second unit device region DR12 may have different dimensions
and/or different gaps from each other. Accordingly, the first unit
device region DR11 may be configured to transmit electromagnetic
waves of a first wavelength range, and the second unit device
region DR12 may be configured to transmit electromagnetic waves of
a second wavelength range different from the first wavelength
range. The resonance wavelength may vary according to the
dimensions, such as length, width, and thickness, of a plurality of
slots constituting one unit device region, and the Q-factor and the
transmittance may vary according to the gap of the slots. Also, the
gap of the slots may considerably affect the resonance wavelength.
As such, at least two of the unit device regions DR11-DR16 may be
configured to transmit electromagnetic waves of different
wavelength ranges. The unit device regions DR11-DR16 may be all
configured to transmit electromagnetic waves of different
wavelength ranges. In some cases, however, at least two of the unit
device regions DR11-DR16 may be configured to transmit
electromagnetic waves of substantially the same wavelength
range.
[0158] Although FIG. 24 illustrates a case in which each of the
unit device regions DR11-DR16 includes two slots, for example, the
slots S11a and S11b of DR11, according to another exemplary
embodiment, at least two of the unit device regions DR11-DR16 may
include different numbers of slots, and an example thereof is
illustrated in FIG. 25.
[0159] FIG. 25 is a plan view of an optical device (array device)
D110 including a plurality of optical unit devices, according to
another exemplary embodiment.
[0160] Referring to FIG. 25, at least two of a plurality of unit
device regions DR21, DR22, DR23, DR24, DR25, and DR26 constituting
an optical device (array device) D110 may include different numbers
of slots. The properties of the unit device regions DR21-DR26 may
be variously controlled through the control of the number of slots,
the gap between slots, and the dimensions (length/width/thickness)
of slots. As such, when the number of slots is included in
variables, the properties control of the unit device regions
DR21-DR26 may be further facilitated.
[0161] The optical devices (array devices) D100 and D110 described
with reference to FIGS. 24 and 25 may form a sort of a metasurface
or a metamaterial structure. As a plurality of slots are formed in
each unit device region in one conductive material layer, for
example, a metal layer, the optical devices D100 and D110 as
illustrated in FIGS. 24 and 25 may be easily manufactured. The
slots may be easily formed by using a lithography process.
Accordingly, the optical devices D100 and D110 may be easily
manufactured. In FIGS. 24 and 25, each of the unit device regions
DR11-DR16 and DR21-DR26 may correspond to one pixel region.
[0162] FIG. 26 is a cross-sectional view of a spectral device
employing an optical device (optical unit device) according to an
exemplary embodiment.
[0163] Referring to FIG. 26, a first array device portion A100 may
include a plurality of optical unit devices. The first array device
portion A100 may correspond to, for example, the optical devices
(array devices) D100 and D110 described with reference to FIGS. 24
and 25, or an optical device (array device) modified therefrom.
Also, at least two of the optical unit devices constituting the
first array device portion A100 may be configured to transmit
electromagnetic waves of different wavelength ranges. Each of the
optical unit devices constituting the first array device portion
A100 may include a plurality of slots. At least two of the optical
unit devices, for example, slots constituting a first optical unit
device and slots constituting a second optical unit device, may
have different dimensions (length/width/thickness) and/or having
different gaps. For example, first slots constituting the first
optical unit device and second slots constituting the second
optical unit device may have different dimensions and/or different
gaps. Although the sizes and gaps of the first slots to the eighth
slots are illustrated to be similar to each other for convenience
of explanation, the first slots to the eighth slots may actually
have different sizes and/or gaps.
[0164] A second array device portion A200 may include a plurality
of detectors (optical detectors) DT1, DT2, DT3, DT4, DT5, DT6, DT7,
and DT for detecting electromagnetic waves passing through the
first array device portion A100. The detectors DT1-DT8 may
one-to-one (1:1) correspond to the optical unit devices of the
first array device portion A100. The detectors DT1-DT8 may be
referred to as a sort of pixels. The detectors DT1-DT8 may include
various types of unit devices (sensors) for converting incident
light (incident electromagnetic waves) to electric signals. For
example, the detectors DT1-DT8 may include photodiodes or charge
coupled devices (CCD) or complementary metal oxide semiconductor
(CMOS) devices. The detectors DT1-DT8 may detect light of different
wavelength ranges .lamda.l-.lamda.8. However, the detailed
structures of the detectors DT1-DT8 are exemplary and may be
variously changed. Also, at least two of the detectors DT1-DT8 may
be configured to detect light of the same wavelength range.
[0165] FIG. 27 is a cross-sectional view of a spectral device
employing an optical device (optical unit device) according to
another exemplary embodiment.
[0166] According to another exemplary embodiment, as illustrated in
FIG. 27, an intermediate layer N100 may be further provided between
the first array device portion A100 and the second array device
portion A200. The intermediate layer N100 may control a gap between
the first array device portion A100 and the second array device
portion A200. The thickness of the intermediate layer N100 may be
about several nanometers to several thousands of nanometers, for
example, about 10 nm to about 2000 nm. The intermediate layer N100
may include a transparent material with respect to electromagnetic
waves of a wavelength range of interest. The intermediate layer
N100 may be a substrate material or another material layer that is
not the substrate.
[0167] FIG. 28 is a cross-sectional view of a spectral device
employing an optical device (optical unit device) according to
another exemplary embodiment.
[0168] According to another exemplary embodiment, as illustrated in
FIG. 28, a cover layer C100 may be further provided on the first
array device portion A100. The cover layer C100 may protect the
first array device portion A100. The cover layer C100, similar to
the intermediate layer N100, may include a transparent material
with respect to electromagnetic waves of a wavelength range of
interest. The cover layer C100 may be a sort of a substrate or
another material layer that is not the substrate. In the structure
of FIG. 28, in some cases, the intermediate layer N100 may not be
used.
[0169] FIG. 29 is a cross-sectional view of a spectral device
employing an optical device (optical unit device) according to
another exemplary embodiment.
[0170] According to another exemplary embodiment, as illustrated in
FIG. 29, a focusing element array L100 may be further provided on
the first array device portion A100. The focusing element array
L100 may be, for example, a microlens array. Although the cover
layer C100 may be provided between the first array device portion
A100 and the focusing element array L100, in some cases, the cover
layer C100 may not be used. Also, the structure of the focusing
element array L100 is exemplary and may be variously changed.
[0171] A spectral device (spectrometer) having the structure as
illustrated in FIGS. 26 to 29 may have a small size less than
several cm .times. several cm, or a size of several mm .times.
several mm or less. In this state, a size of each of the detectors
DT1-DT8, that is, a pixel size may be tens of micrometers or less
or several micrometers or less. The pixel size may be as small as
about 1 .mu.m or less. According to exemplary embodiments, because
a high Q-factor and superior light efficiency may be obtained by
spacing a relatively small number of slots by an appropriate gap to
correspond to one pixel region, compact/ultra compact spectral
device (spectrometer) having high performance may be easily
implemented.
[0172] Additionally, in the exemplary embodiments, the optical unit
device including a plurality of slots, and the optical device
(array device) including a plurality of optical unit devices may
have a thickness that is less than the resonance wavelength, that
is, a subwavelength thickness. For example, the thickness of the
optical unit device and optical device (array device) may be about
1 .mu.m (1000 nm) or less. In an example, when the resonance
wavelength is about 1.5 .mu.m (1500 nm), the thickness of the
optical unit device may be about 300 nm. In this state, the
thickness of the optical device (array device) including a
plurality of optical unit devices may be about 300 nm. As the
length of a wavelength of interest increases, the thickness of the
optical unit device may be reduced. A material film including a
plurality of slots may be used as the optical unit device and the
optical device (array device). Because the optical unit device or
the optical device (array device) may be used as an optical filter
or a spectral device, the thickness of the optical filter or the
spectral device may be the subwavelength thickness. This may be
tens of times to hundreds of times thinner than the thickness of an
existing optical filter or spectral device. Accordingly, according
to the exemplary embodiment, the optical device having a thin
thickness (very thin thickness) and superior properties may be
easily implemented.
[0173] FIG. 30 is a schematic block diagram of an optical
measurement apparatus 1000 employing a spectral device according to
an exemplary embodiment.
[0174] Referring to FIG. 30, the optical measurement apparatus
(hereinafter, measurement apparatus) 1000 may be an apparatus to
measure/analyze properties/information of an object (object to be
tested) OBJ in an optical method. The object OBJ may include a
living body of a human or animal or food, in some cases, a
non-living thing. Also, the object OBJ may be a sample for
analyzing air pollution or water pollution. The measurement
apparatus 1000 may include a light source portion 100 for
irradiating light L10 to the object OBJ and an optical sensor
portion 200 for detecting or sensing light L10' that is generated
by the light source portion 100 and modulated by the object OBJ.
The light source portion 100 may include, for example, a light
source that generates light of an IR range. The optical sensor
portion 200 may include the spectral devices according to the
exemplary embodiments, for example, the spectral devices described
with reference to FIGS. 19 to 29.
[0175] The measurement apparatus 1000 may include a controller 500
connected to the light source portion 100 and the optical sensor
portion 200. The controller 500 may include a signal processor 300
for processing signals measured by the optical sensor portion 200.
Also, the controller 500 may further include a user interface 400.
The user interface 400 may include an input portion and an output
portion. The input portion may be a device used by a user to input
a command to the measurement apparatus 1000, and may be implemented
by, for example, a keypad, a touch screen, a speech recognition
device, or a button type input device. The output portion is a
device for outputting an analyzed result and may include a display
device or may be implemented by, for example, a sound system, a
vibration device, or a printer. The controller 500 may be connected
to the light source portion 100 and the optical sensor portion 200
by a wired or wireless method. Although illustrated in the
drawings, the measurement apparatus 1000 may further include a
memory or a communication portion.
[0176] The light source portion 100 and the optical sensor portion
200 may constitute one "spectrometer." Also, the light source
portion 100 and the optical sensor portion 200 may constitute one
"spectral sensor module." In some cases, the entire measurement
apparatus 1000 may be one "spectrometer." In this case, the light
source portion 100, the optical sensor portion 200, the signal
processor 300, and the user interface 400 may constitute one
"spectrometer."
[0177] When the light source portion 100 and the optical sensor
portion 200 constitute one "spectral sensor module," the spectral
sensor module may be configured to sense the light reflected and/or
scattered by the object OBJ. Also, the spectral sensor module may
be configured to sense the light transmitting through the object
OBJ. While the former may be referred to as the "reflective
spectral sensor module," the latter may be referred to as the
"transmissive spectral sensor module." The reflective spectral
sensor module is exemplarily described with reference to FIG. 31,
and the transmissive spectral sensor module is exemplarily
described with reference to FIG. 32.
[0178] FIG. 31 is a diagram of an optical arrangement of the
spectral sensor module applicable to the optical measurement
apparatus 1000 of FIG. 30, according to an exemplary
embodiment.
[0179] Referring to FIG. 31, according to the exemplary embodiment,
the spectral sensor module may be of a reflective type. The
spectral sensor module may be configured such that light L11
generated by a light source 110 is reflected and/or scattered by
the object OBJ and then light L11' that is reflected and/or
scattered by the object OBJ is sensed by an optical sensor 210.
[0180] A light path change member 112 for changing a path of the
light L11 generated by the light source 110 may be provided.
Although the light path change member 112 is illustrated to have a
prism shape, this is exemplary and the light path change member 112
may have a shape of a beam splitter or a plate mirror. Also, the
light path change member 112 may not be provided according to the
position of the light source 110. The light L11 whose path is
changed by light path change member 112 may be irradiated toward
the object OBJ. An aperture 114 may be further provided between the
light path change member 112 and the object OBJ. The light L11'
that is reflected and/or scattered by the object OBJ may be sensed
by the optical sensor 210. A lens 16 for focusing the reflected
and/or scattered light L11' on the optical sensor 210 may be
further provided. However, the structure of the reflective spectral
sensor module illustrated in the drawing is exemplary and may be
variously changed.
[0181] FIG. 32 is a diagram of an optical arrangement of a spectral
sensor module applicable to the optical measurement apparatus 1000
of FIG. 30, according to another exemplary embodiment.
[0182] Referring to FIG. 32, the spectral sensor module according
to the exemplary embodiment may be of a transmissive type. The
spectral sensor module may be configured such that light L12
generated by a light source 120 passes through the object OBJ and
light L12' that passed through the object OBJ is sensed by an
optical sensor 220.
[0183] A light path change member 122 for changing a path of the
light L12 generated by the light source 120 may be provided. The
light L12 whose path is changed by the light path change member 122
may be irradiated toward the object OBJ. An aperture 124 may be
further provided between the light path change member 122 and the
object OBJ. The light L12' that passes through the object OBJ may
be sensed by the optical sensor 220. A lens 126 for focusing the
light L12' that passed through the object OBJ on the optical sensor
220 may be further provided. However, the structure of the
transmissive spectral sensor module illustrated in the drawing is
exemplary and may be variously changed.
[0184] At least a part of the optical the measurement apparatus
1000 according to the above-described exemplary embodiments may
constitute at least a part of a mobile device or a wearable device.
The mobile device may be, for example, a mobile phone (smart
phone), and the wearable device may have a various shape, for
example, a wristwatch type device, a wristband type device or
bracelet type device, a glasses type device, a hairband type
device, or a ring type device.
[0185] FIG. 33 is a diagram of a mobile device, to which an optical
measurement apparatus according to an exemplary embodiment is
applicable. In the exemplary embodiment, the mobile device is a
mobile phone.
[0186] In FIG. 33, a left image (A) shows a front surface of a
mobile phone and a right image (B) shows a rear surface of the
mobile phone. An optical sensor of an optical measurement apparatus
according to an exemplary embodiment may be provided to be exposed
from the front surface or rear surface of the mobile phone.
Alternatively, the optical sensor may be provided to be exposed
from a side surface (including upper, lower, left, and right sides)
of the mobile phone.
[0187] FIG. 34 is a diagram of a wearable device, to which an
optical measurement apparatus according to an exemplary embodiment
is applicable. In the exemplary embodiment, the wearable device is
a wristwatch type device.
[0188] Referring to FIG. 34, the wristwatch type device may include
a device main body portion (watch portion) W10 and a band portion
B10. At least a part of the optical measurement apparatus according
to the exemplary embodiment may be applied to the band portion B10,
to the device main body portion W10, or separately to the band
portion B10 and the device main body portion W10.
[0189] According to another exemplary embodiment, a part of the
optical measurement apparatus is provided on a wristwatch type
device of FIG. 34, and the other part may be provided on the mobile
device (mobile phone) of FIG. 33. Also, the wearable device and the
mobile device may be interactive and may have data communication
therebetween.
[0190] FIG. 35 is a diagram of an optical measurement apparatus
according to another exemplary embodiment. Referring to FIG. 35, a
mobile device MD1 may be provided and an auxiliary device AD1 is
electrically connected to the mobile device MD1. The mobile device
MD1 may be a sort of mobile phone (smart phone), and the auxiliary
device AD1 may be a device including the spectral device
(spectrometer) according to the exemplary embodiment. The mobile
device MD1 and the auxiliary device AD1 may be may be connected to
each other by a wireless or wired communication method. After an
object OBJ is optically measured by using the auxiliary device AD1,
measured data may be output via the mobile device MD1.
[0191] Because the spectral device (spectrometer) according to the
exemplary embodiment is compact/ultra compact, the spectral device
(spectrometer) may be easily applied to a small mobile device, a
small wearable device, or a small auxiliary device.
[0192] The optical measurement apparatuses (measurement systems)
according to the exemplary embodiments may be applied not only to
the mobile device, the wearable device, and the auxiliary device,
which are described with reference to FIG. 33 to FIG. 35, but also
to medical devices used in hospitals or medical examination
organizations, mid- or small-sized medical devices provided in
public organizations, compact medical devices carried by
individuals, and various health care apparatuses.
[0193] The optical unit devices according to the exemplary
embodiments, and an array device including a plurality of optical
unit devices, may be applied to optical apparatuses other than the
spectrometer. For example, the optical unit devices and the array
device may be applied to imaging apparatuses, bandpass filters, for
example, IR bandpass filters, multi-bandpass filters, or display
apparatuses. The imaging apparatus, for example, IR cameras, may
include wavelength-selector arrays and pixel arrays, and the
optical unit devices according to the exemplary embodiments may be
applied to the wavelength-selector arrays. Also, the optical unit
devices and the array devices may be applied to hyper-spectral
imaging devices. The hyper-spectral imaging devices may be devices
using remote sensing technologies. Although wavelengths of an IR
range are mainly described in the above-described exemplary
embodiments, the optical unit devices and the array devices
according to the exemplary embodiments may be used to wavelength
ranges other than the IR range, for example, a visible ray range or
microwave range. In this case, technical fields utilizing the
optical unit devices and the array devices may be further
extended.
[0194] Although in the above description a lot of items are
presented in detail, the items are interpreted to be detailed
examples of exemplary embodiments rather than restrictions to the
range of an inventive concept. For example, one of ordinary skill
in the art would understand that the structure of the optical unit
device described with reference to FIGS. 3, 8, 10, 11, 19 to 23,
the structure of the optical device (array device) described with
reference to FIGS. 24 and 25, the structure of the spectral device
described with reference to FIGS. 26 to 29, the structure of the
optical measurement apparatus described with reference to FIGS. 30
to 35 may be modified in various ways. In a detailed example, at
least two of a plurality of slots included in one optical unit
device may have two different sizes. When one optical unit device
includes three or more slots, at least two of a plurality of gaps
defined by the three or more slots may be different from each
other. Also, one optical unit device may include five or more
slots. In addition, the structures of the optical device (array
device), the spectral device, and the measurement apparatus may be
modified in various ways. The fields of optical devices to which
the optical unit device and the array device are applied may be
variously changed.
[0195] It may be understood that exemplary embodiments described
herein may be considered in a descriptive sense only and not for
purposes of limitation. Descriptions of features or aspects within
each exemplary embodiment may be considered as available for other
similar features or aspects in other exemplary embodiments. While
exemplary embodiments have been described with reference to the
figures, it will be understood by those of ordinary skill in the
art that various changes in form and details may be made therein
without departing from the spirit and scope as defined by the
following claims.
* * * * *